IMS again
 

This has been discussed to death in various forums but I'm looking for a fresh look at the problem. I have a 1998 and I do question the current findings.

If the bearing was underrated, then all IMS bearings would fail at roughly the same point but they don't. The figures I have seen are 1% of the older cars and 8% of the newer ones. However some cars do +100K miles and no problem. I don't believe that that IMS bearing is underrated. It is highly loaded but within spec. It could have been designed better, however, its not the problem.

There has to be some other factor causing the failure.

Here are a few that I'm thinking of

1 Could a low oil level reduce the oil to the bearing

2 Could it be either high or low RPM be a factor, ie slow town driving or many track days

3 As time has gone on, the zinc, (high pressure lubricant) in oils has been reduced to save the catalytic converters. Maybe other suppliers of oils could have a lower zinc contents. In my vintage race bike, I went through rockers quite regularly till I swapped to a high Zinc oil. Problem gone.

4 were the cars were driven in the odd high temperature days and the weight oil was therefore below the recommended value.

5 Oil does break down over time and changes its viscosity. Were the oil change intervals extended?

6 were the cars standing for long periods of time ? Oil dripped down thus when started the bearings were dry.

Keen to hear other peoples opinions.

Some reading

https://www.timken.com/pdf/5892_Bearing%20Damage%20Analysis%20Brochure.pdf

Spent years chasing 2 stroke seizes till I read this article.

http://www.marshland.co.nz/ftp/Files/topend_rebuild6.pdf

Basically all seizes are oil failures.

Cheers Wallace

Hi Wallace. You're basing all you scenarios on the oil, but the oil level, quality, viscosity, etc should have no 'bearing' (pun intended), because the bearing is sealed and has grease in it.

One thing the oil CAN do over time is become acidic and break down the seal and eventually wash away the grease.

From what I've read, lubrication is the major factor, but it has nothing to do with the oil level or viscosity, it has to do with the bearing losing its grease. Which is why some solutions use an open bearing and constantly pump oil into the bearing, whether it's from an external line or through the IMS tube itself.

Hey, we need to rehash a subject that must have been discussed hundreds of times on this forum already. And thousands of time on all the Boxster forums taken together. Then add in the 911 forums...

I'm with Mike on this..... I think I could probably find 5 posts online SOMEWHERE that read nearly word-for-word like the post below.

You're "keen to hear others thought"? Probably not too keen, or you'd have read then already. Your post rehashes a line of thinking that's been argued dozens of times just in the 2 years I've owned my car. Don't know what'd make your query any different?

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I agree with Mike. However on another note, Mike, which tires do you recommend and which oil are you running? I can't find anything online.

Sorry my mistake. I read about several suppliers with oil fed solutions and never having worked on a motor, didn't realize it was a sealed bearing. That eliminates a huge number of issues.

There are however many sealed bearings that last virtually forever. If so few fail, then it could have been a batch problem from the supplier.

This discussion however made me rethink 'hope it lasts' option to and oil fed solution.

Thanks for the input.

And now for those tires and oil, I will !!!!!!!!!!!!!!!!!!!!!!!! Ha Ha

Yeah, the oil-fed solutions are changing the bearing to an open bearing, which requires constant lubrication. (iiuc)

For me, I wish someone would develop a replacement bearing that's more like a traditional crank bearing, with a direct oil feed to it, and bearing "shells". This makes so much more sense to me, and would have the happy benefits of still staying largely "in-place" if the bearing failed, si timing remains close, meaning no other parts in the motor get damaged. It would also be easily replaceable if damaged.

But that would be FAR too easy for the Porsche community.... Haha. I mean, it'd be almost sacrilegious to put a simple and robust bearing in a motor with 5 chains, all those ramps and hydraulic tensioners, the craziest Air/Oil separator system I've ever seen.... etc etc.

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It's already been done, sort of, but it still uses an external oil feed:

IMS Solution – The only permanent fix for M96/M97 engines intermediate shaft bearing problem

I love how they call it the "Permanent fix" but only guarantee it for 5 years!

You can always buy a 987.2. The IMS bearing in those are guaranteed for life. In addition, I will personally guaranty it.

haha! What I paid for my 986 plus the cost of another motor, if I should ever need one, is still less than half the cost of a used 987.2

So when you (Your significant other) puts a new roll of toilet paper on the holder, is it spin towards the wall or away from it????

I'll bet you can't search that here

There are several IMS kits which provide roller bearings which use pressurized oiling.

There is a kit using a plain bearing similar to the one on the other end of the camshaft and this kit adds pressurized oiling (The Solution).

I think the roller bearing is a disaster, regardless of pressurized oiling.

I'm talking about a plain bearing.

https://uploads.tapatalk-cdn.com/201...8894c8b14a.jpg

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You just described the IMS Solution.

As I wrote in post #8, it's already been done.

IMS Solution – The only permanent fix for M96/M97 engines intermediate shaft bearing problem

Plain bearing.

They call it a "permanent fix" but it's only guaranteed for 5 years! HA!

And exactly how long did Porsche warrantee the car originally?

Away from the wall. I don't want the inaugural application to be with paint, wallpaper, tile, or cement.

To my best recollection, Porsche never made the claim that the car will last forever, or that it's "the last car you'll ever need."

My point is that if they make the claim of being the "permanent fix", they should put their money where their mouth is and guarantee it forever.

Porsche didn’t call it the “Permanent Vehicle” or “Transportation Solution”, suggesting that the car would never fail.
The “IMS Solution”, however, does suggest that (with a 5 year warranty).

Calling something “permanent” or the “solution” without the data to support it is deceptive, at best.

Let's see: Porsche sold you a $50K+ car (original price depending upon the year) and gave you a "limited" 4 year warrantee. LN sold you a $1K part, and warrantied it for 5 years, in a market where 1 year parts warranties are rare, and 30 days is more the norm. And you are complaining?